Methods and apparatus to count audience members

ABSTRACT

Methods and apparatus to count audience members are disclosed. An example method includes identifying a first audience member present at a first time, incrementing a stored first count of a number of times the first audience member is present during a day part corresponding to the first time, incrementing a stored tuning occasion count, identifying a second audience member present at a second time, incrementing a stored second count of a number of times the second audience member is present during the day part, incrementing the stored tuning occasion count, determining a probability that an unidentified audience member is the first audience member based on the first count, the second count, and the tuning occasion count, and counting the first audience member based on a comparison of the probability to a threshold.

RELATED APPLICATIONS

This patent arises from a continuation of U.S. patent application Ser.No. 09/883,546, filed Jun. 18, 2001, the entirety of which is herebyincorporated by reference.

FIELD OF THE INVENTION

The present invention relates to audience measurement and, moreparticularly, to method and apparatus to count audience members.

BACKGROUND

It is customary in the field of audience research to employ ameasurement apparatus with each program receiver within each of aplurality of statistically selected locations in order to determinetuning data. Program receivers include television receivers, radioreceivers, computers, and/or other devices capable of being tuned toprograms that are distributed over the air, over cable systems, by wayof satellites, etc. Tuning data, for example, includes the identity ofthe channel or station to which the program receiver is tuned and/or theidentity of the program to which the program receiver is tuned.

It is further customary to provide a manual input 20 device that can beused by those audience members who are actually in an audience of areceiver to indicate their identities to the measurement apparatus. Thismanual input is frequently provided in the form of a Peoplemeter whichnot only allows each audience member to manually enter a correspondingaudience member identification but also provides a visual statusindicator for showing which of the audience members have indicated thatthey are currently in the receiver's audience. For example, this visualstatus indicator may comprise a plurality of selectively illuminatedlight emitting diodes disposed on a box placed adjacent to a receiverand within the field of view of the audience members.

The manual input device alternatively may be a battery-powered remotecontrol or other remote device that includes a keypad and an infra-redpulse transmitter which permit an audience member to manually enter themember's identity and to transmit that identity by way of infra-redpulses to the measurement apparatus or other data collector. Themeasurement apparatus or other data collector also provides a visualstatus indication as discussed above. An exemplary remote control ofthis type is disclosed by Kiewit in U.S. Pat. No. 4,876,736. Still otheralternative devices which collect manually entered audience memberidentification data and which use the receiver to indicate the currentlyrecorded audience status are known.

The tuning data from the measurement apparatus and the audience memberidentities from the manual input device are commonly time stamped withthe times of each tuning event and/or of each change in audiencecomposition. The time stamped tuning and audience member records arethen stored in a store and forward unit within the statisticallyselected location for subsequent forwarding to a data collection centraloffice, such as on a daily or other basis.

Because audience members forget from time to time to enter theiridentities, it is known to prompt the audience members to manually entertheir identities. 15 However, it is well known in audience measurementthat systems relying on prompting signals sent to cooperating audiencemembers must be concerned about the frequency of those promptingsignals. If a cooperating individual perceives the prompting signals asbeing so frequent as to be annoying, he or she may stop cooperating. Onthe other hand, if the prompting is too infrequent, the cooperatingindividual may forget to enter data at appropriate times.

McKenna et al., in U.S. Pat. No. 4,816,904, discloses an arrangement inwhich a prompting message is displayed on a television screen overlaidon viewer selected programming by mixing the prompting message with thevideo signal being sent to the display. However, McKenna et al. do notteach how to effectively regulate the prompting frequency.

Therefore, the present invention is directed to the use of tuning and/oraudience response data in an 10 adaptive prompting algorithm to selectthe frequency with which prompting occurs.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features and advantages of the present invention willbecome more apparent from a detailed consideration of the invention whentaken in conjunction with the drawings in which:

FIG. 1 is a schematic diagram of an audience measurement system inaccordance with an exemplary 20 embodiment the present invention;

FIG. 2 is a schematic diagram of an audience measurement apparatus ofthe audience measurement system shown in FIG. 1;

FIG. 3 is a schematic diagram of a data storage I 5 and forwarding unitof the audience measurement system shown in FIG. 1;

FIGS. 4A and 4B form a flow chart of a prompting program that may beused in connection with the audience measurement system of FIG. 1; and,

FIGS. 5-8 are tables of exemplary data useful in the explanation of theoperation of the audience measurement system of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

As shown in FIG. 1, an audience measurement system 10 is provided at astatistically selected location 12 in which known audience members arepresent. The statistically selected location 12, for example, may be ahousehold. The audience measurement system 10 includes a portable remotecontrol device 14 which controls a receiver 16. The receiver 16, forexample, may be a television receiver as shown in FIG. 1, although thereceiver 16 could instead be a radio, a computer, or any other receiverthat is capable of being tuned to programs distributed over the air,over cable, by way of satellite, or by way of other communicationmethodology to the statistically selected location 12.

The portable remote control device 14 may have a user interface such asa keypad which includes buttons to allow an audience member to enterchannel numbers, to change channels up and down, to increase anddecrease volume, to mute the receiver 16, and to turn the receiver 16 onand off. Thus, the portable remote control device 14 can be used from aremote position 18 in order to change the channel, volume level, and soon of the receiver 16.

The keypad of the portable remote control device may also permitaudience members to identify themselves when they are in the audience ofthe receiver 16. The names and appropriate demographic information ofeach of the audience members may be associated with a corresponding oneof the buttons of the keypad and may be suitably stored in anappropriate memory. Accordingly, when an audience member presses abutton for identification purposes, the time and date of the press, theappropriate identification, and the appropriate demographic informationmay be stored with the corresponding tuning data.

The audience measurement system 10 is arranged to log data on audiencemembership (hereinafter “audience member identification data”). Theaudience measurement system 10 may be arranged to also log tuning dataregarding the programs and/or channels to which the receiver 16 istuned. Periodically, the logged data is transmitted over a network 20 toa data collection central office 22. The network 20 may be any mechanismfor conveying the logged data to the data collection central office 22.For example, the network 20 may be a public switched telephone network,as is conventional practice in the audience measurement art.

The portable remote control device 14 may be used to enter memberidentification data into a measurement apparatus 24 which is installedadjacent to the receiver 16. The measurement apparatus 24 may also bearranged to acquire tuning data from the receiver 16 in any conventionalmanner in addition to the audience member identification data acquiredfrom the portable remote control device 14. Additionally oralternatively, the audience member identification data may be entered bydevices other than the portable remote control device 14. For example, aPeoplemeter may be used to enter member identification data into themeasurement apparatus 24 as discussed above. Additionally oralternatively, the audience member identification data may be entered byuse of switches mounted directly on the measurement apparatus 24, or theaudience member identification data may be entered into the measurementapparatus 24 by use of an electronic program guide (EPG). If an EPG isused, the EPG may also be used to enter tuning data into the measurementapparatus 24. The acquired tuning and audience member identificationdata can be communicated to the data collection central office 22 by avariety of techniques known to those skilled in the art.

The audience measurement system 10 includes a data storage andforwarding unit 26 which collects the tuning and audience memberidentification data from the measurement apparatus 24 and which storesthe tuning and audience member identification data until a scheduledforwarding time when the tuning and audience member identification dataare forwarded to the data collection central office 22. The data storageand forwarding unit 26 may also store and forward tuning and audiencemember identification data collected from a measurement apparatus,similar to the measurement apparatus 24, associated with each of theother receivers (not shown) located in the statistically selectedlocation 12. The audience measurement system 10, the measurementapparatus 24, and/or the data storage and forwarding unit 26 may bereferred to herein as an audience meter.

The measurement apparatus 24 can comprise logic and a memory so that thecurrent tuning data can be acquired and determined by the measurementapparatus 24 based upon channel selection inputs from the portableremote control device 14.

Alternatively or additionally, the measurement apparatus 24 may receivea signal replica from a signal detector 34. For example, this signaldetector 34 may be in the form of a video signal source detector such asthat disclosed by Chan, in U.S. Pat. No. 5,889,548. This video signalsource detector may be positioned as taught in the Chan application toacquire a replica of a video signal from an input to a CRT of thereceiver 16.

Alternatively or additionally, the signal detector 34 may be in the formof a microphone which acquires a replica of an audio output from aspeaker of the receiver 16. Accordingly, the signal detector 34 isarranged to non-intrusively acquire from the receiver 16 a replica ofthe video and/or audio signal processed by the receiver 16.

The signal replica acquired by the signal detector 34 can then beprocessed by the measurement apparatus 24 according to a variety oftuning measurement methodologies. For example, (i) an ancillary videoand/or audio code (such as a source identification (SID) code)identifying the tuned program or channel can be read from the signalreplica, if present, (ii) video and/or audio feature signaturescharacteristic of the tuned program can be extracted from the signalreplica and compared to reference signatures in order to identify theprogram or channel, and/or (iii) the signal replica can be correlatedwith a contemporary reference signal obtained by a reference scanningtuner controlled by the measurement apparatus 24 in order to identifythe program or channel.

As a further alternative, the signal detector 34 may be arranged todetect the local oscillator frequency of the receiver 16. This localoscillator frequency indicates the channel to which the receiver 16 istuned, as is known in the audience measurement art.

Moreover, whether or not the signal detector 34 is employed, themeasurement apparatus 24 may receive an ON/OFF input from an ON/OFFsensor 36. The ON/OFF sensor 36, for example, may be an inductive sensorwhich determines that the receiver 16 is on by detecting the inductivesignals emanating from the receiver 16. In the case where the receiver16 is a television receiver, the ON/OFF sensor 36 may be an inductivesensor which, as is well known, determines that the receiver 16 is on bydetecting the horizontal retrace frequency of the CRT of the receiver16. Alternatively, the ON/OFF sensor 36 may have a photodetector probepositioned in relation to the screen display of the receiver 16 so thatchanging light levels or the amount of light emanating from the screendisplay can be used to indicate when the receiver 16 is on or off.Alternatively, the ON/OFF sensor 36 can be any other type of sensorsuitably arranged to determine the on/off status of the receiver 16.

In controlling the receiver 16, the portable remote control device 14preferably operates in the manner of a conventional universal remotecontrol capable of controlling two or more tuner appliances, such as atelevision receiver, a VCR, and/or a cable converter. Such a universalremote control conventionally uses several different code sets so thatit can operate in multiple user-selected modes. One or more of thesemodes can be used to transmit a tuning or other command (e.g., a fastforward command sent to a VCR) to the currently active tuner (e.g., thetuner of receiver 16 or of a set-top cable converter or of a VCR)controlling the receiver 16. In addition, one of the modes of theportable remote control device 14 is also used to transmit audiencemember identification data to the measurement apparatus 24.

Optionally, the keypad of the portable remote control device 14 may beprovided with dedicated buttons associated with each of the audiencemembers. Accordingly, these dedicated buttons may be used by theaudience members exclusively for member identification.

The measurement apparatus 24 as shown in FIG. 2 includes amicroprocessor 52 suitably connected to a transceiver 54, the signaldetector 34, a ROM 56, a RAM 58, the ON/OFF sensor 36, and an interface60. The transceiver 54, coupled to the microprocessor 52 executing aprogram stored in the ROM 56, is used to receive tuning status and/oraudience member identification data from the portable remote controldevice 14. The tuning status data, along with the current audiencemember identification data and a time stamp, are temporarily saved inthe RAM 58. Optionally or alternatively, the measurement apparatus 24may also respond to the signal detector 34, as discussed above, in orderto identify the tuned program from codes, signatures, or correlations,or to determine the tuned channel such as by detecting the localoscillator frequency of the receiver 16. This information can betemporarily stored in the RAM 58. The measurement apparatus 24additionally may be arranged to determine the ON/OFF status of thereceiver 16 from the ON/OFF sensor 36. The ON/OFF status of the receiver16 is used as discussed below in the prompting of audience members toenter their identifications by use of the portable remote control device14 (or otherwise) in accordance with a prompting program describedbelow. As discussed above, the measurement apparatus 24 transmits theON/OFF, tuning, and audience member identification data to the datastorage and forwarding unit 26 by means of the interface 60.

Accordingly, the measurement apparatus 24 through execution by themicroprocessor 52 of a program stored in the ROM 56 acquires and/ordetermines tuning data associated with the tuning of the receiver 16 andtemporarily stores this tuning data in the RAM 58. The measurementapparatus 24 also acquires and/or determines the ON/OFF status of thereceiver 16 and temporarily stores this status in the RAM 58. Moreover,the measurement apparatus 24 receives audience member identificationdata and temporarily stores this data in the RAM 58. The measurementapparatus 24 through use of the interface 60 communicates any or all ofthis data to the data storage and forwarding unit 26. For example, themeasurement apparatus 24 may communicate this data to the data storageand forwarding unit 26 immediately upon acquisition.

As shown in FIG. 3, the data storage and forwarding unit 26 includes amicroprocessor 82 suitably coupled to an interface 84, a ROM 86, a RAM88, and an interface 90. The interface 84 and the interface 60 supportcommunications between the measurement apparatus 24 and the data storageand forwarding unit 26, and the interface 90 supports communicationbetween the data storage and forwarding unit 26 and the data collectioncentral office 22 as discussed above.

The ROM 86 stores a program 100 represented by the flow chart shown inFIGS. 4A and 4B in order to collect and forward tuning and audiencemember identification data from each measurement apparatus 24 associatedwith a corresponding receiver 16 in the statistically selected location12 and to provide prompting instructions to audience members through theappropriate measurement apparatus 24 so as prompt the audience membersto identify themselves. The prompting management implemented by the 15program 100 relies on audience participation history of each possibleaudience member, by receiver and by source identification (SID) class. ASID is an ancillary code that is inserted into programs so as toidentify the programs or their sources.

Other technologies, such as navigation characteristics, may providevaluable information for prompt management. Navigation characteristicsindicate the manner in which certain audience members tune the receiver16. For example, one of the audience members may channel surf. Thus, anytime that channel surfing is detected, the probability that the channelsurfing audience member is in the audience may be increased. The program100 is particularly useful where the measurement apparatus 24 cannotclearly detect channel changes.

An instance of the program 100 as shown in FIGS. 4A and 4B may beprovided at the data storage and forwarding unit 26 for each of thereceivers at the statistically selected location 12. Alternatively, theprogram 100 as shown in FIGS. 4A and 4B may be arranged to execute atthe data storage and forwarding unit 26 and to accommodate all of thereceivers at the statistically selected location 12. As a furtheralternative, an instance of the program 100 may be provided at themeasurement apparatus 24 associated with each of the receivers at thestatistically selected location 12.

As shown in FIG. 4A, when the program 100 receives data indicating thatthe receiver 16 has been turned on, the program 100 at a block 102acquires tuning data related to the receiver 16 and stores that data inthe RAM 88. At a block 104, the program 100 instructs the appropriatemeasurement apparatus 24 to immediately prompt the audience members inthe audience of the receiver 16 to identify themselves. This promptingmay be effected by on-screen displays on the receiver 16, by a visibledisplay provided by the measurement apparatus 24 or the portable remotecontrol device 14, by an audible message provided by the measurementapparatus 24 or the portable remote control device 14, etc.

The responsive audience member identification data is received at ablock 106. In the case where the audience member identification data isprovided by the portable remote control device 14 and the program 100 isexecuting at the data storage and forwarding unit 26, this audiencemember identification data is received through use of the transceiver 54and is communicated to the data storage and forwarding unit 26 by themeasurement apparatus 24. Alternatively, the measurement apparatus 24may be provided with input keys, switches, and the like in which casethe measurement apparatus 24 receives the audience member identificationdata directly and communicates to the data storage and forwarding unit26. The program 100 at a block 108 stores the audience memberidentification data in the RAM 58 or the RAM 88, as appropriate, and, ata block 110, also updates the SID class tables as appropriate.

These tables are used by the data storage and forwarding unit 26 tomaintain a running accumulator of audience composition. The runningaccumulator is a count of the number of times each audience member logsonto each of the receivers 16 in the statistically selected location 12and is maintained by time period and by class of SID code.

The table of FIG. 5 illustrates a single month's accumulation of datafor a single household for all SID classes. As the table of FIG. 5indicates, days are broken into day parts. The table is further brokeninto the various audience members present in the statistically selectedlocation 12, and the table further breaks down each audience member byreceiver. As shown in FIG. 5, the audience members are indicated bytheir sex and age, and the receivers are indicated by their location(such as bedroom, living room, and kitchen). However, instead of sex andage, other identifiers such as names may be used to identify theaudience members, which may be particularly useful where multiplemembers having the same sex and roughly the same age are present at thestatistically selected location 12. Moreover, receiver locationidentities other that bedroom, living room, and kitchen may be assignedto the receivers used in the statistically selected location 12, whichmay be particularly useful where there are multiple rooms of the sameroom type in the statistically selected location 12.

The exemplary data provided in the table of FIG. 5 indicates, forexample, that the 35-49 year old female audience member used thereceiver in the bedroom eighteen 10 times to receive programs at 6:00 AMduring the month covered by the table of FIG. 5, that the 35-49 year oldfemale audience member used the receiver in the bedroom nineteen timesto receive programs at 6:30 AM during the month covered by the table ofFIG. 5, that the 35-49 year old female audience member used the receiverin the bedroom twenty-two times to receive programs at 7:00 AM duringthe month covered by the table of FIG. 5, that the 35-49 year old femaleaudience member used the receiver in the bedroom twenty-one times toreceive programs at 7:30 AM during the month covered by the table ofFIG. 5, and so on. The table holds similar data for the other audiencemembers at the statistically selected location 12 and for other dayparts.

The tuning occasions section of the table stores data related to howmany times during each day part each receiver 16 at the statisticallyselected location 12 was used, regardless of the number of audiencemembers in the audience of that receiver during that time and month.Thus, for example, the 35-49 year old female audience member used thereceiver in the bedroom eighteen times to receive programs at 6:00 AMduring the month covered by the table of FIG. 5, and the 35-49 year oldmale audience member used the receiver in the bedroom one time toreceive a program at 6:00 AM during the month covered by the table ofFIG. 5. However, there were only eighteen tuning occasions during whichthe receiver in the bedroom was used at 6:00 AM for the relevant month,because the 35-49 year old female audience member and the 35-49 year oldmale audience member used the receiver in the bedroom at 6:00 AM on thesame day during the month covered by the table of FIG. 5.

As another example, the 35-49 year old female audience member used thereceiver in the living room eight times to receive programs at 6:00 PMduring the month covered by the table of FIG. 5, the 35-49 year old maleaudience member used the receiver in the living room one time to receivea program at 6:00 PM during the month covered by the table of FIG. 5,and the 12-17 year old female audience member used the receiver in theliving room fourteen times to receive programs at 6:00 PM during themonth covered by the table of FIG. 5. However, there were only fifteentimes that the receiver in the living room was on with someone in theaudience during the 6:00 PM day part for the relevant month, because onseveral occasions there were more than one audience members in theaudience of the living receiver during that day part. Thus, there wereonly fifteen tuning occasions during which the receiver in the livingroom was used at the 6:00 PM day part for the relevant month.

The counts section of the table stores data related to the sum of thedata by receiver and day part for the relevant month. Thus, for example,the 35-49 year old female audience member used the receiver in thebedroom eighteen times to receive programs at 6:00 AM during the monthcovered by the table of FIG. 5, and the 35-49 year old male audiencemember used the receiver in the bedroom one time to receive a program at6:00 AM during the month covered by the table of FIG. 5. Thus, the countfor the bedroom receiver is 18+1=19 for the 6:00 AM day part for therelevant month.

As another example, the 35-49 year old female audience member used thereceiver in the living room eight times to receive programs at 6:00 PMduring the month covered by the table of FIG. 5, the 35-49 year old maleaudience member used the receiver in the living room one time to receivea program at 6:00 PM during the month covered by the table of FIG. 5,and the 12-17 year old female audience member used the receiver in theliving room fourteen times to receive programs at 6:00 PM during themonth covered by the table of FIG. 5. Thus, the count for the livingroom receiver is 8+1+14=23 for the 6:00 PM day part for the relevantmonth.

The data in the table of FIG. 5 do not show any SID-specificinformation, but instead represent a marginal layer collapsing over allSID codes. Data collapsing is useful whenever insufficient data has beencollected upon which to make predictions about the audience members inthe audience of a receiver at a given day part. For example, datacollapsing is particularly useful during the first few months of initialdata collection because insufficient data is likely to have beencollected upon which to make predictions about the audience members inthe audience of a receiver at a given day part.

The table shown in FIG. 5 is only exemplary of the way in which the datamay be stored. The data alternatively could be stored in an accumulatortable for all sets in the household. This accumulator table isincremented each time there is a change in tuning status or audiencecomposition and includes data for every person, time period, set, andSID class. Thus, the accumulator table may simply log each tuning eventand each audience composition event in chronological order.

As a further alternative, such an accumulator table may be used to storedata as they are accumulated during a month and then transferred to thetype of month table shown in FIG. 5 at the end of the relevant month.Other alternatives are also possible.

The tables store the basic information which is evaluated for eachreceiver prior to a scheduled prompt. These tables maintained by themeasurement apparatus 24 or the data storage and forwarding unit 26preferably includes four separate tables, a table for the current month,a table for the current month−1, a table for the current month−2, and atotal of all months up to and including the current month−3. Thesetables permit a variable weighting of data by recency of behavior whichmay be used, for example, during data collapsing.

Thus, this recency weighting is accomplished by combining all four monthtables on a weighted basis into a 10 master table that is used for eachreceiver to determine whether or not to deliver the scheduled prompt tothe audience at that receiver. For example, if the recency weights are2.1, 0.3, 0.3, 0.3, then every cell in the four month tables describedabove would be combined, giving a 15 weight of 2.1 to the data in thecurrent month table and equal weights of 0.3 to the data in the otherthree tables.

The program 100 at a block 112 determines whether it is time to evaluatethe data in the tables discussed above. For example, the block 112 mayuse an elapsed time timer such that the block 112 determines that it istime to perform its evaluation when the elapsed time timer accumulatesan amount of time T. The time T between evaluations may be set to 42minutes or any other number of minutes which is deemed appropriate.Accordingly, at T after the receiver 16 has initially been turned on,the program 100 at the block 112 initiates an evaluation of the datastored in the tables to determine if prompting should be suppressed.Thus, a prompt will be given after the passage of T unless theevaluation indicates that prompting should be suppressed.

The evaluation is a probability-based heuristic. 10 The tuning andaudience composition history at the statistically selected location 12is mathematically summarized and represented in multidimensional tablesof counts. Each time a prompt is scheduled to be delivered, thisinformation is evaluated, and, if the mathematical structure of audiencecomposition in the household is such that the probability of a specificaudience composition exceeds a certain threshold value, then the promptis suppressed.

The heuristic is an algorithm for parsimoniously summarizing andretrieving knowledge stored in the tables. In a densely populated table,the simplest algorithm would search the cell most similar to the currentcondition, compute straightforward probabilities for each, and, if theprobability of a single tuning composition exceeded a certain threshold,the prompt would be suppressed until the next cycle.

The objective is to determine audience composition. Rather than treatingthis determination as a problem in combinatorics, this determination maybe treated as a problem of individual tuning at a receiver, by SID andday part, but including terms that include co-receiving history andcurrent response to an alternate receiver (co-location).

The operation of the heuristic may be illustrated with the samplefrequency tables shown in FIGS. 6, 7, and 8. The tables shown in FIGS. 6and 7 correspond to the frequency tables for two SID classifications,SID 11 and SID 12. These SID classes, for example, divide the programsby program type such as daytime drama, prime time drama, sports whichcan be further broken down into subtypes such as football, baseball,etc. Accordingly, Each SID may be assigned to one of these classes. Thetable in FIG. 8 contains a total of the data in the monthly tables (inthe example here, the total of the data in the tables of FIGS. 6 and 7).

If the block 112 determines that it is time to make an evaluation (e.g.,time T has passed since the last prompt decision), a block 114determines whether the number of persons who have logged in (i.e.,identified themselves as being in the audience) equals the number ofpersons who have been counted in the audience. Counting of persons maybe implemented by using electric eyes, proximity, or other sensing tocount the audience members as they enter and leave a reception areaassociated with the receiver 16. A counter 90 is shown in FIG. 1 forthis purpose. The measurement apparatus 24 collects count informationfrom the counter 90 and passes this count information to the datastorage and forwarding unit 26 as appropriate. If the block 114determines that the number of persons who have logged in is not equal tothe number of persons who have been counted in the audience, a block 116permits the prompt to be given to the audience members at the receiver16 corresponding to the program 100.

On the other hand, if the block 114 determines that the number ofpersons who have logged in is equal to the number of persons who havebeen counted in the audience, a block 118 determines a variable NUMBERas a result of dividing a data value COUNTS by a data value TUOCC. Thedata value COUNTS is taken from the counts row, at the receiverlocation, during the day part, and for the SID class corresponding tothe current day part and the current SID of the program being receivedby the receiver corresponding to the program 100. For example, if thecurrent day part is 6:30 AM if the SID from the program being receivedby the appropriate receiver is in SID class 11, and if the appropriatereceiver is the bedroom receiver, the data value for COUNTS is 20.

The data value TUOCC is taken from the tuning occasions row, at thereceiver location, during the day part, and for the SID classcorresponding to the current day part and the current SID of the programbeing received by the receiver corresponding to the program 100. Forexample, if the current day part is 6:30 AM, if the SID from the programbeing received by the appropriate receiver is in SID class 11, and ifthe appropriate receiver is the bedroom receiver, the data value forTUOCC is 19.

Therefore, the variable NUMBER is determined as 20/19. If either thenumerator or denominator which is used to determine the variable NUMBERfalls below a predetermined threshold, it may be necessary to collapseeach cell in the tables from right to left (SID, and then receiver)until this threshold is reached because there are otherwise insufficientdata in the SID tables on which a prediction can be based. Followingsuch data collapsing, the variable NUMBER may be recomputed.

A block 120 determines whether the variable NUMBER exceeds acorresponding threshold. If the variable NUMBER does not exceeds thecorresponding threshold, the block 116 permits the prompt to be given tothe audience members at the receiver 16 corresponding to the program100. On the other hand, if the variable NUMBER exceeds the correspondingthreshold, a block 122 rounds NUMBER to the nearest integer and comparesthe rounded NUMBER to the current persons count. This current personscount may be derived, for example, by summing the number of audiencemembers who have logged into the measurement apparatus 24 at thereceiver 16 corresponding to the program 100. Alternatively, the currentpersons count may be derived by using the sensing described above tocount the audience members as they enter and leave a reception areaassociated with the receiver 16. If the rounded NUMBER is different thanthe current persons count, the block 116 permits the prompt to be givento the audience members at the receiver 16 corresponding to the program100.

On the other hand, if the rounded NUMBER is not different than thecurrent persons count, the variable NUMBER is consistent with history asrepresented by the data in the tables so that the audience members canbe further evaluated by the program 100. Therefore, if the roundedNUMBER is not different than the current persons count, a block 124 setsa variable PREDICTED PERSON equal to the person having the maximumprobability of being in the audience of the receiver 16 corresponding tothe program 100. For example, using the tables of FIGS. 6-8 and asdescribed above, the person having the maximum probability of being inthe audience of the bedroom receiver at the current time (6:00 AM+T)watching a program in SID class 11 is the 35-49 year old female.Therefore, the variable PREDICTED PERSON is set to the 35-49 year oldfemale.

Also, the block 124 computes the probability that the PREDICTED PERSON(the 35-49 year old female in the example) is in the audience bydividing the number of times the 35-49 year old female tuned into aprogram having the relevant SID class and during the current day part bythe count for that SID class and day part. For example, the probabilitythat the 35-49 year old female is in the audience of the bedroomreceiver which is tuned to a program having the SID class 11 at andduring the current time (6:00 AM+T) is 19/20 using the table of FIG. 6.This probability 19/20 may be adjusted by a lead-in adjustment factorF_(LI). This lead in factor F_(LI) is used to adjust the computedprobability when the PREDICTED PERSON was in the audience of therelevant receiver during the immediately preceding day part. This leadin factor F_(LI) may be a predetermined number set to a suitable valuegreater than one and is multiplied by the computed probability in orderto increase the computed probability.

Following the processing at the block 124, the program 100 at a block126 determines whether the probability calculated at the block 124 isless than a predetermined threshold. If the probability calculated atthe block 124 is less than this predetermined threshold, the block 116permits the prompt to be given to the audience members at the receiver16 corresponding to the program 100. It is noted that there may beinsufficient data in the tables at this point during the execution ofthe program 100, in which case the data may be collapsed as indicatedabove. However, if the data is so collapsed, it is likely that theprobability calculated at the block 124 is less than a predeterminedthreshold, so that it is correspondingly likely that a prompt will bepermitted.

On the other hand, if the probability calculated at the block 124 is notless than the predetermined threshold, the program 100 at a block 128determines whether the audience member, who is in the audience of thereceiver 16 corresponding to the program 100 and who has entered his orher identification into the corresponding measurement apparatus 24, isthe PREDICTED PERSON. If the audience member, who is in the audience ofthe receiver 16 corresponding to the program 100 and who has entered hisor her identification into the corresponding measurement apparatus 24,is not the PREDICTED PERSON, the block 116 permits the prompt to begiven to the audience members at the receiver 16 corresponding to theprogram 100.

On the other hand, if the audience member, who is in the audience of thereceiver 16 corresponding to the program 100 and who has entered his orher identification into the corresponding measurement apparatus 24, isthe PREDICTED PERSON, then the program 100 at a block 130 suppressesprompting.

After the block 116 permits the prompt to be given 10 to the audiencemembers at the receiver 16 corresponding to the program 100, or afterthe block 130 suppresses prompting, the elapsed time timer used by theblock 116 is reset, and the program 100 returns to the block 116 inorder to repeat the execution of blocks 112-130 at 6:00 AM+2T and ateach increment of T thereafter.

At a particular time during the day, the data storage and forwardingunit 26 communicates its stored tuning and audience memberidentification data to the data collection central office 22.

Other events may also be used by the block 116 of the program 100 totrigger prompts. Such other events include, for example, a channelchange when no audience member is logged in, the passage of apredetermined number of days when a particular household member has notlogged in, the passage of a predetermined number of days when a shortterm visitor has not logged in, no log ins when the receiver 16 isturned on, no log ins of particular household members (such as children)when the receiver 16 is tuned to particular programs (such as children'sprogramming), and the like.

As described above, navigation characteristics may provide valuableinformation for prompt management. Navigation characteristics indicatethe manner in which certain audience members tune the receiver 16. Thus,in the same way that tuning to individual programs or tuning duringspecific day parts or on specific sets may be correlated with aparticular household member as described above, tuning styles may alsobe associated with individual household members. Accordingly, whentuning patterns are evaluated, the styles in which people select theirprograms may also be evaluated.

Tuning styles can be described by a variety of terms depending on whichparadigm is being used to conceptualize receiver tuning. Tuning stylescan be considered to mean or include “navigational patterns”, “biometricsignatures,” or “keystroke dynamics.” These styles can be characterizedby some very simple “statistics” or by more complex forms ofrepresenting knowledge.

“Statistics” are formally defined by mathematicians as a mathematicalprojection of a vector or set of data onto a single or simple set ofparameters. Thus, statistics are used, in effect, to summarize data. Amean is an example of a statistic which may be used to summarize a setof data. However, in summarizing data, certain knowledge about the data,such as variance, kurtosis, skew, and, of course, the exact value ofeach data point, is lost. Therefore, the statistics used to summarizethe data may or may not be sufficient.

“Sufficiency” in theoretical statistics refers to the ability of a“statistic” to reproduce the required detail of a data distribution. Insome households, a simple statistic can “sufficiently” represent tuningstyle. One such statistic is the average number of stations or programstuned per time period. For example, if one audience member views“appointment television” (i.e, an audience member tunes to a channelcarrying a selected program and stays on that channel throughout most orall of the selected program), the average number of stations “hit” perhalf hour will be very small. But if another audience member is a“surfer,” the average number of “hits” per half hour will be much, muchlarger. While summaries of the tuning habits of these audience membersmay cause knowledge of variance and skew to be lost, the sheerdifference between the average velocities (average rate of channelchange) of these two audience members is sufficient to distinguishbetween these audience members. Thus, in this example, the mean rateof_is sufficient to identify the individual.

However, in some households, there may be several members that have thesame average rate of channel changing (velocity). In this case, the onlyway to distinguish these households is to consider channel velocityalong with other parameters of tuning which might provide “sufficiency”in order to identify the recent presence of a household member.

For example, for every time period T (e.g., ½ hr), the average number ofchannels tuned during that half hour may be recorded and stored in thetables of FIGS. 6-8 for every individual logged on to a receiver.However, velocity may not be sufficient to distinguish between peoplewhose “instantaneous rate of change”, often called acceleration, isdifferent. For example, two people may average twenty channel hits perhalf hour with one of the people methodically surfing by watching everyother hit for a minute or two, while the other of the two people surfsthrough twenty channels, finds an appealing program, and then watchesfor a half hour. The average velocity is not a sufficient statistic todistinguish these two audience members. However, their acceleration canbe used to distinguish between them.

There are several statistics that can represent “acceleration.” Anexemplary statistic to represent acceleration is given by the followingdescription. If it assumed that the time period is thirty. minutes, thefollowing ratio may be used to characterize acceleration:

$\frac{\# \mspace{14mu} {of}\mspace{14mu} {channels}\mspace{14mu} {in}\mspace{14mu} {past}\mspace{14mu} 30\mspace{14mu} {minutes}}{\begin{matrix}{\# \mspace{14mu} {of}\mspace{14mu} {minutes}\mspace{14mu} {in}\mspace{14mu} {which}\mspace{14mu} {channel}} \\{{was}\mspace{14mu} {changed}\mspace{14mu} {in}\mspace{14mu} {past}\mspace{14mu} 30\mspace{14mu} {minutes}}\end{matrix}}$

For example, if twenty channels were hit in ten separate minutes oftuning, then the acceleration is 20/10 or a modest 2. On the other hand,if twenty channels were hit in two minutes of surfing, then theacceleration is 20/2 or a moderate ten.

In some homes, even “acceleration” may not be sufficient to distinguishbetween audience members. For example, it may be the case that where anaudience member surfs in a program or channel space is the key todistinguishing between two audience members. Therefore, in suchhouseholds, a learning heuristic can be used to classify the “cluster ofchannels” that an audience member surfs and to match this surfingcluster to the “clusters of programs” to which an audience member tunes.Accordingly, classification and matching may be done specifically todistinguish between the channel-surfing patterns of two audience memberswith similar velocity and acceleration histories.

Accordingly, the probability determined at the block 124 can be adjustedup or down by velocity, acceleration, and/or program clustering.Alternatively, any combination of these factors can be included in theprogram 100 as one or more decision blocks.

Certain parameters used by the program 100 may be downloadable from thedata collection central office 22 to the measurement apparatus 24 or thedata storage and forwarding unit 26 and stored in the RAM 58 or the RAM88. For example, the parameter T may be downloaded.

Certain modifications of the present invention have been discussedabove. Other modifications will occur to those practicing in the art ofthe present invention. For example, it is noted that the portable remotecontrol device 14 may function in several different modes as describedabove. However, each of these modes may use a separate correspondingremote control.

Also, the present invention as described above relies on the use ofcertain infrared transceivers. However, it will be appreciated thatother signaling modes, such as ultrasonic or spread-spectrum radio,could instead be employed.

In addition, the present invention as described above relies on the useof transceivers. Instead, a separate receiver and transmitter could beused in place of each transceiver.

Moreover, as discussed above, instead of executing the program 100 atthe data storage and forwarding unit 26, the program 100 can be executedat each measurement apparatus 24 within the statistically selectedlocation 12. In this case, the data storage tables shown in FIGS. 5-8may be modified by eliminating the receiver category. Also in this case,the storing and forwarding function performed by the data storage andforwarding unit 26 can be performed by the measurement apparatus 24 sothat the data storage and forwarding unit 26 can be eliminated.

Furthermore, as described above, the portable remote control device 14according to the first embodiment 15 of the invention transmits tuningcommands which are received by both the controlled tuner and by themeasurement apparatus 24. The controlled tuner responds by effecting thetuning indicated by the tuning command, and the measurement apparatus 24responds by recording the tuning event. Instead, in accordance with theteachings of U.S. Pat. No. 4,876,736, the portable remote control device14 may be arranged to transmit tuning commands using codes recognized bythe measurement apparatus 24 but not by the tuner of the receiver 16.Thus, the measurement apparatus 24 records the tuning event, convertsthe code into a form recognized by the tuner of the receiver 16, andpasses the converted tuning command on to the tuner of the receiver 16.

Also, a different portable remote control device could be assigned toeach person in the household (with additional portable remote controldevices provided to visitors). Each person would then carry his or herportable remote control device within the household. The individual'sportable remote control device 14 can then be arranged to periodicallytransit an identification signal to the measurement apparatus 24 eitherbased upon time increments or based upon a command issued by themeasurement apparatus 24.

Moreover, the prompting permitted by the block 116 may have multiplelevels. For example, at the lowest level, the initial prompt could beflashed for 10 seconds. If the audience responds appropriately, theprogram 100 resumes normal execution. If the audience does not respondappropriately within a predetermined amount of time (e.g. 20 seconds),and the prompt is flashed for 20 seconds at a higher flash rate. If theaudience responds appropriately, the program 100 resumes normalexecution. If the audience still does not respond appropriately, theblock 116 may be arranged to provide an audible tone or a voice command.Different and/or additional levels of prompting may be provided.

In addition, it may be deemed desirable for audience members to manuallyupdate audience composition without prompting as changes in audiencecomposition occur. Prompting serves mainly as a fail-safe, whensufficient time has elapsed without any unprompted change. Therefore,the elapsed time timer used by the block 116 may be reset at each entryof any audience member identification data whether prompted or not.

As an additional contingency, the interval T between prompts could belengthened or shortened in order to reinforce timely entry of audiencechanges. This adjustment of T could be based on the data entryperformance of audience members. For example, if a particular audiencemember typically waits until a prompt appears before reporting anearlier audience change, then the data record will show an improbablyhigh proportion of reported audience changes coinciding with theappearance of the prompt. If this pattern of performance is observed,the program 100 may shorten the interval T between prompts. Shorteningthe interval T between prompts will tend to reduce any possible lagsbetween the occurrence and reporting of audience changes, as well as toprovide a mild negative reinforcement for audience members who fail toreport audience changes as they occur.

Alternatively or additionally, it is possible that 10 audience memberswill report audience changes when they occur and that the intervals Tbetween prompts are shorter than the interval during which no audiencechange actually occurs. If this pattern is observed, it may be that theprompting interval T is shorter than required for this audience member.In this instance, the program 100 may lengthen the interval T betweenprompts in order to provide a positive reinforcement. Indeed, differentprompting intervals T could be set for various audience members,depending on their previous performance.

Furthermore, the heuristic of the present invention as described aboverelies upon the representation of tuning history and/or style knowledgein the form of a series of probability tables. Such knowledge, however,can be represented in other forms. For example, as receiver tuningevents occur, data relating to these events could be stored in acovariance matrix which could then be evaluated through regression,discriminant, or other parametric techniques which would developprediction scores for each potential household member. Similarly,non-parametric techniques for representing knowledge, such as weighteddigraphs, may be used to represent such knowledge. Conceptually, theheuristic has been described above using the simplest form of knowledgerepresentation. However, an important element of the heuristic is itscapacity to manage user prompts or questions regardless of how suchtuning histories (knowledge) are represented.

Also, as viewed from the standpoint of a meter, audience members havefeatures: what programs they watch, when they watch, with whom theywatch, where they watch, and how they change channels. In somehouseholds, one or two of these statistics may suffice to discriminatebetween audience members. In other households, at certain times of day,many of these statistics may be required. Thus, in a more advanced formof the heuristic described above, aperiodic analysis could be conductedin each household to evaluate the structure, among household members, ofeach of these features. For example, in a two-person household, oneperson may surf while the other tunes by appointment. This householdwould be highly structured with respect to acceleration. In this case,the negentropy, or information content (h²) of acceleration, is veryhigh. In an advanced heuristic, the values of each of these featureswould be weighted by their information content, that is, their abilityto discriminate among audience members. In addition, specific hardwareis described in relation to FIGS. 1, 2, and 3. However, it should beunderstood that other hardware and/or software arrangements may be usedto implement the present invention.

Accordingly, the description of the present invention is to be construedas illustrative only and is for the purpose of teaching those skilled inthe art the best mode of carrying out the invention. The details may bevaried substantially without departing from the spirit of the invention,and the exclusive use of all modifications which are within the scope ofthe appended claims is reserved.

1. A method comprising: identifying a first audience member present in astatistically selected location at a first time; incrementing a storedfirst count of a number of times the first audience member is in thestatistically selected location during a day part corresponding to thefirst time, wherein the first count corresponds to a sourceidentification tuned by a receiver corresponding to the statisticallyselected location at the first time; incrementing a stored tuningoccasion count for the statistically selected location during the daypart and corresponding to the source identification; identifying asecond audience member present in the statistically selected location ata second time; incrementing a stored second count of a number of timesthe second audience member is in the statistically selected locationduring the day part, wherein the second count corresponds to the sourceidentification; incrementing the stored tuning occasion count for thestatistically selected location during the day part and corresponding tothe source identification; determining a probability that anunidentified audience member in the statistically selected location at athird time is the first audience member based on the first count, thesecond count, and the tuning occasion count; and counting the firstaudience member based on a comparison of the probability to a threshold.2. A method as defined in claim 1, wherein determining the probabilityis based on a third count of a number of times the first audience memberis in the statistically selected location during the day part, whereinthe third count corresponds to a second source identification tuned toby the receiver.
 3. A method as defined in claim 1, wherein determiningthe probability is based on a third count of a number of times the firstaudience member is in a second statistically selected location duringthe day part, wherein the third count corresponds to the sourceidentification.
 4. A method as defined in claim 1, further comprisingsuppressing an identification prompt when the probability is greaterthan a threshold.
 5. An apparatus, comprising: a processor; and a memorycoupled to the processor, the memory storing machine readableinstructions which, when executed by the processor, cause the processorto: identify a first audience member present in a statistically selectedlocation at a first time; increment a stored first count of a number oftimes the first audience member is in the statistically selectedlocation during a day part corresponding to the first time, wherein thefirst count corresponds to a source identification tuned by a receivercorresponding to the statistically selected location at the first time;increment a stored tuning occasion count for the statistically selectedlocation during the day part and corresponding to the sourceidentification; identify a second audience member present in thestatistically selected location at a second time; increment a storedsecond count of a number of times the second audience member is in thestatistically selected location during the day part, wherein the secondcount corresponds to the source identification; increment the storedtuning occasion count for the statistically selected location during theday part and corresponding to the source identification; determine aprobability that an unidentified audience member in the statisticallyselected location at a third time is the first audience member based onthe first count, the second count, and the tuning occasion count; andcount the first audience member based on a comparison of the probabilityto a threshold.
 6. An apparatus as defined in claim 5, wherein theinstructions are further to cause the processor to determine theprobability is based on a third count of a number of times the firstaudience member is in the statistically selected location during the daypart, wherein the third count corresponds to a second sourceidentification tuned to by the receiver.
 7. An apparatus as defined inclaim 5, wherein the instructions are further to cause the processor todetermine the probability based on a third count of a number of timesthe first audience member is in a second statistically selected locationduring the day part, wherein the third count corresponds to the sourceidentification.
 8. An apparatus as defined in claim 5, wherein theinstructions are further to cause the processor suppress anidentification prompt when the probability is greater than a threshold.9. A computer-readable medium comprising computer-readable instructionswhich, when executed by a processor, cause the processor to at least:identify a first audience member present in a statistically selectedlocation at a first time; increment a stored first count of a number oftimes the first audience member is in the statistically selectedlocation during a day part corresponding to the first time, wherein thefirst count corresponds to a source identification tuned by a receivercorresponding to the statistically selected location at the first time;increment a stored tuning occasion count for the statistically selectedlocation during the day part and corresponding to the sourceidentification; identify a second audience member present in thestatistically selected location at a second time; increment a storedsecond count of a number of times the second audience member is in thestatistically selected location during the day part, wherein the secondcount corresponds to the source identification; increment the storedtuning occasion count for the statistically selected location during theday part and corresponding to the source identification; determine aprobability that an unidentified audience member in the statisticallyselected location at a third time is the first audience member based onthe first count, the second count, and the tuning occasion count; andcount the first audience member based on a comparison of the probabilityto a threshold.
 10. A computer-readable medium as defined in claim 9,wherein the instructions are further to cause the processor to determinethe probability is based on a third count of a number of times the firstaudience member is in the statistically selected location during the daypart, wherein the third count corresponds to a second sourceidentification tuned to by the receiver.
 11. A computer-readable mediumas defined in claim 9, wherein the instructions are further to cause theprocessor to determine the probability based on a third count of anumber of times the first audience member is in a second statisticallyselected location during the day part, wherein the third countcorresponds to the source identification.
 12. A computer-readable mediumas defined in claim 9, wherein the instructions are further to cause theprocessor suppress an identification prompt when the probability isgreater than a threshold.